Portable patient weighing device

ABSTRACT

A system and method for measuring the weight of patients in a wheelchair are disclosed, including two portable weight measurement devices, wherein the devices measure the weight imposed on two wheels of a four wheel wheelchair, and a receiver that accepts weight measurement data from the portable weight measurement devices. The weight data exchanged between the two portable weight measurement devices and/or with the receiver may be transported over wireless connections.

CROSS REFERENCE TO RELATED APPLICATIONS

N/A

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to medical patient weighing, and, moreparticularly, to a portable device, system and method for weighingambulatory and non-ambulatory patients.

2. Description of the Background

It is known that persons confined to a wheelchair often need to beweighed as part of a medical check up or follow-up. For many of theseindividuals, stepping off a wheelchair and onto a weight scale isdifficult, or impossible, to accomplish. Consequently, weighing both thewheelchair and the patient, and subtracting the weight of the wheelchair, is a practical method of weighing. This practice has becomecommonplace. Such a simple procedure may, in fact, be quite involved,because the weighing device must accommodate the wheelchair, whichgenerally requires ramps and a platform scale, for example. As such,wheelchair users ordinarily are weighed at a physician's office,hospital, nursing home, clinic, or the like, using a platform scale,which weighing, due to the inconvenience of the need to travel, mayoccur once a month or less. Such infrequent weighing renders weightcontrol programs quite difficult to maintain. In addition to those usingwheelchairs, often those requiring crutches or walkers must be seated inwheelchairs for weighing due to the difficulty in maintaining balance onan ordinary scale while utilizing crutches or a walker.

Due to the size of platform scales, platform scales are generally foundprincipally in clinics, hospitals, nursing homes, or rehabilitationcenters with a significant number of mobility-disabled patients.Consequently, physicians rarely have office platform scales, not onlybecause such scales occupy a disproportionate amount of floor space inrelation to usage, but also because, even with foldable ramps, suchscales occupy valuable storage space. Although physician's weighingchairs may be available with built-in scales, those confined towheelchairs may find it inconvenient or dangerous to be transferredbetween chairs for a procedure as routine as weighing.

In response to the deficiencies inherent in available weighing systemsfor the mobility disabled, portable weighing devices including twolaterally displaced, electrically connected and rigidly aligned weighingmodules have been developed. An example of one such system is documentedin U.S. Pat. No. 5,414,225. The weighing device taught therein isdesigned for the conventional manually-operated wheelchair supported bytwo front caster wheels and two rear main wheels. A notable feature ofthe above-referenced device is the rigidly adjustable scissors-likeadjustment between the two weighing pads. The rigidly adjustable padsmust be pre-extended to the correct width of the wheelchair before use.A continuously variable width adjustment would be attractive because itpermits easy last-minute adjustment of the weighing pads by an operator.

Additionally, it would be advantageous if a weighing scale could beutilized by both non-ambulatory and ambulatory patients, whereinambulatory patients could step on the scales and be weighed without theuse of the wheelchair, and wherein non-ambulatory patients may be pushedonto the same scale in a wheelchair. Thus, dual purpose weighing padscould be used for both purposes, and a smaller platform scale in adoctor's office setting would not be needed.

Therefore, a need exists for a portable, fully adjustable wheelchairscale that can additionally serve as a substitute for a platform scale.

SUMMARY OF THE INVENTION

A system for measuring the weight of patients on a wheelchair includestwo portable weight measurement devices, wherein the devices measure theweight imposed on two wheels of a wheelchair, and a receiver, whereinthe receiver accepts weight measurement data from the portable weightmeasurement devices and wherein the weight data exchanged between thetwo portable weight measurement devices and/or the receiver istransported over wireless connections. The system may further include amedical record server interface, wherein the medical record serverinterface accepts patient weight data for storage into a patient recorddatabase.

A method of measuring and recording the weight of a patient on awheelchair includes measuring the partial weight of an empty wheelchairby placing a front pair of wheelchair wheels on two portable weightmeasuring devices and sampling a first weight, measuring the partialweight of an empty wheelchair by placing a pair of rear wheelchairwheels on the two portable weight measuring devices and sampling asecond weight, combining the first and second weight, and storing thecombined first and second weight as the wheelchair weight, measuring thepartial weight of a patient sitting in a wheelchair by placing the frontwheels on the two portable weight measuring devices and sampling a thirdweight, measuring the partial weight of a patient sitting in awheelchair by placing the rear wheels on the two portable weightmeasuring devices and sampling a fourth weight, combining the third andfourth weight, and storing the combined third and fourth weight as thepatient and wheelchair weight, and subtracting the wheelchair weightfrom the patient and wheelchair weight to arrive at a patient weight.

Thus, the present invention provides a system and method for a portable,fully adjustable wheelchair scale that can additionally serve as asubstitute for a platform scale.

BRIEF DESCRIPTION OF THE DRAWINGS

Understanding of the present invention will be facilitated byconsideration of the following detailed description of a preferredembodiment of the present invention, taken in conjunction with theaccompanying drawings, in which like numerals refer to like parts and inwhich:

FIG. 1 is a side view of a wheelchair depicting the use of portableweighing devices;

FIG. 2 is a block diagram of an embodiment of the present invention;

FIG. 3 is a depiction of a portable weighing device;

FIG. 4 is a block diagram of an embodiment of the present invention;

FIG. 5 is a block diagram of an embodiment of the present invention;

FIG. 6 is a block diagram of an embodiment of the present invention;

FIG. 7 is a block diagram of an embodiment of the present invention;

FIG. 8 is a flow diagram of an aspect of the present invention;

FIG. 9 is a flow diagram of an aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

It is to be understood that the figures and descriptions of the presentinvention have been simplified to illustrate elements that are relevantfor a clear understanding of the present invention, while eliminating,for purposes of clarity, many other elements found in a typicalpatient-safety device. Those of ordinary skill in the art will recognizethat other elements are desirable and/or required in order to implementthe present invention. However, because such elements are well known inthe art, and because they do not facilitate a better understanding ofthe present invention, a discussion of such elements is not providedherein. The disclosure hereinbelow is directed to all such variationsand modifications to configurations for portable wheelchair scales asknown, and as will be apparent, to those skilled in the art.

FIG. 1A shows a portable wheelchair weighing device 100 a,b, deployedwherein the caster wheels 104 of a wheelchair 102 are first rolled upthe integral ramps into a concave load cell portion of the weighingdevice. Portable wheelchair weighing device 100 a,b may include twoassemblies, wherein one assembly serves one of two wheels, and whereineach assembly integrates a load cell for loading of a wheel withoutrolling of the wheel once in place. In FIG. 1A, weighing device 100 a isplaced under one caster wheel 104, and device 100 b is placed under asecond caster wheel (not visible). FIG. 1B shows the portable wheelchairweighing device 100 a,b deployed wherein each of the main wheels 106 ofa wheelchair 102 are rolled up respective integral ramps onto theconcave weighing device. The portions of the weight of the wheelchairsupported by each wheel of the two front caster wheels, and the two rearmain wheels may be successively summed and/or subtracted, oralgorithmically calculated, or taken as a direct weight measurementwherein all four wheels are loaded simultaneously, for example. Further,the weight of the wheelchair, where known, may be entered into theweighing device manually, such as by typing on a keypad, or scanning abar code on the wheelchair whereby the weight is evidenced, forsubtraction from the weight measured with the patient and the wheelchairin combination on the weighing device. The weight of the occupant maythereby be calculated and stored or displayed.

Conventional wheelchairs are diverse with respect to dimensions, andthese differences may affect weight readings. Critical dimensions forweighing include the wheelbase (longitudinal distance between caster andmain wheel axes), center-of gravity (vertical distance between center ofoccupied wheelchair mass and floor level), and the tread (lateraldistance between each of the caster wheels and between each of the mainwheels). The effect of different wheelbases and differentcenters-of-gravity on weight readings may additionally depend on thetilt of the wheelchair when either the caster wheels or the main wheelsare on the scale platform. As is well known in the art, if the height ofthe scale platform above floor level is less than a roughly 4millimeters (0.16 inches) clearance, tilt errors can be discounted onweight readings. Consequently, scale platform heights above 4 mm are notdiscussed at length herein. However, it is well known by those of skillin the art that mathematical algorithms may be used to determine thecorrect weight if the height of the scale platform is greater than 4 mm.

Additionally, should the weighing device 100 incorporate multiple loadcells non-simultaneously measuring, an effective weight measurement mayutilize an algorithm. Such algorithms are discussed in U.S. Pat. No.5,004,058 and U.S. Pat. No. 6,260,003 B1. Consequently, the currentinvention is not limited to a method of weight conversion utilizing asingle load cell, or two load cells. Multiple load cells may also beutilized with an appropriate compensation in the calculation of patientweight, based on, for example, the type and number of load cells used inthe portable weighing device.

For example, if a patient in a wheelchair is to be measured, a handheldcontroller may prompt the user to enter the wheelchair weight, such asby typing in the information or by scanning in the information which maybe available on a bar coded sticker on the wheelchair, for example.Assuming that two portable weighing device scales are being used, thecontroller may prompt the user to place the front caster wheels of theempty wheelchair on the scales. The user may roll the front wheels ofthe wheelchair up the ramped transducers of the scale and allow thewheels to settle into the scale grooves for stability. A weightmeasurement of the front wheel weight may be taken by activating theappropriate control of the handheld unit. The controller may then promptthe user to remove the front wheels and place the rear or main wheels ofthe wheelchair on the transducers in the same manner as the frontwheels. A weight measurement of the rear wheels may then be taken byactivating the appropriate control on the handheld unit, and the totalweight may then be calculated using an algorithm. Naturally, if theweight of the wheelchair is already known, then the weighing of theempty wheelchair is unnecessary.

Next, the weight of the patient seated in the wheelchair may be taken.The handheld controller may prompt the user to place the front wheels ofthe occupied wheelchair on the transducers. The occupied wheelchair maybe rolled up onto the transducer ramps, and the front wheels may beplaced into the transducer grooves for added stability, in addition to,for example, locking the front wheels. A front wheel measurement of theoccupied wheelchair may be taken when the user activates the appropriatecontrol of the handheld unit. The wheelchair may then be rolled off thetransducers, turned around, and the rear wheels rolled up the transducerramp and into the grooves of the transducers for a measurement, and thetotal weight may then be calculated algorithmically

If an ambulatory patient is to be weighed, the user may place coversover the wheel grooves on the transducers, if present, for example, andthen may initialize the weighing devices with the handheld controller.The walking patient may stand directly on the transducers, and a directpatient weight may be taken when the user activates the appropriatecontrol on the handheld controller.

FIG. 2 is a block diagram illustrating an embodiment of the presentinvention utilizing portable weighing device 100 a,b, in conjunctionwith a receiver of weight data, which receiver may include a controller202 and/or a Medical Record Server Interface. The controller 202 may bea handheld controller 202, such as, for example, an electroniccontroller, a PDA, a handheld computer, or the like, or may be anycontroller known to those skilled in the art, such as a PLC or computer.Medical record server interface may be, for example, a networkinterface, such as a wired or wireless interface to a network server,such as a medical record server on which medical records, such aspatient weights, are stored. The controller 202 may be included in, orexclusive of, the medical record server interface. The portable weighingdevices 100 a,b may each include a transducer scale portion and acontrol portion, for example. The transducer scale portion may include aload cell portion, as discussed hereinabove, to prevent rolling of awheel of a wheel chair. Alternatively, the transducer portion mayinclude thereon, or in proximity therewith, a wheel lock to lock thewheels to prevent rolling. Alternatively, the load cell portion mayinclude a shape correspondent to the bottom of a human foot, to allow anambulatory patient to stand on, for example, one or two of thetransducers, and to allow for the taking of a weight measurementtherefrom. In these exemplary embodiments, the handheld controller mayallow an operator to input the weight-taking methodology, such as“standing patient”, “2 wheels of chair”, or “4 wheels of chair”, toallow for a correspondent adjustment in algorithms used to generate theweight measurement. Any number of transducers and load cells may beemployed correspondent to wheelchairs having differing numbers ofwheels, such as three or four wheeled wheelchairs, as will be apparentto those skilled in the art.

An exemplary scale transducer portion 212 of the portable weighingdevice 100 a is depicted in FIG. 3 a. The transducer portion may includean integral ramp shape, as well as one or more transducers 216positioned in a manner apparent to those of skill in the art toaccurately measure stress/strain as an indicator of weight. FIG. 3 bdepicts an exemplary cross section of the integral ramp of thetransducer assembly 212. With respect to FIG. 3B, height H may be 4 mmor less in height if no correction due to the tilt of the wheelchair isto be made within the controller 214 portion of the portable weighingdevice 100 a, as discussed hereinabove.

Returning now to FIG. 2, portable weighing devices 100 a and b may beinterconnected via cable 206 between transducers 212, 216, such asbetween transducer controllers 214 and 218. Cable 206 may permit thecommunication of weight data from controller 2 218 to controller 1 214,for example. Alternately, controller 2 218 may interface directly withthe handheld controller 202, such as by a cable, to provide the sameconnectivity that controller 1 214 has with the handheld controller 202via cable 208.

The handheld controller 202 may permit the monitoring and control of theweighing operation, as set forth hereinabove. Handheld controller mayinclude an internal controller or processor running software thereon,thereby enabling the controller to display instructions to the user, andto display, for example, the results of the weight measurement. In theexemplary embodiment of FIG. 2, the handheld controller 202 may includeinterfaces for the reception of controller 1 and controller 2 data viacable 208. The handheld controller 202 may format the data for receptionby the medical record server interface 204 via cable 210, for example.Alternatively, data may be stored within the transducers 212, 216 orcontrollers 214, 218 for later download, or may be downloaded directlyto the medical record server interface from the controllers 214, 218.Cables 208 and 210 may be any hardwire interface commonly known to thoseof skill in the art, such as a twisted pair, a shielded twisted pair,coaxial cable, or optical cable, for example.

The Medical Record Server Interface 204 of FIG. 2 may be connected, suchas via an interface 210, such as a cable interface 210, to the handheldcontroller. This interface may allow the weight data of a patient to beuploaded to the patients medical records. This interface may take otherforms, such as wireless, infrared, radio frequency, or the like, forexample.

FIG. 4 is a block diagram illustrating an embodiment of the presentinvention, wherein a wireless interface is utilized between controller 1and controller 2 of the portable weighing devices 100 a,b. The wirelessinterface may be any interface known to those skilled in the art, suchas an RF interface or an infrared interface. The interface may bebi-directional in that controller 1 may query controller 2 to requestthe most recently acquired weight data, and controller 2 may thenrespond to the data request by providing the weight data sample tocontroller 1. Alternatively, controller 2 may provide data without arequest from controller 1. Controller 1 may package both controller 1and controller 2 data for transmission to the handheld controller 202,or may transmit the combined data directly to the record serverinterface 204, such as for storage or calculation.

The wireless interface 402 may include an RF interface, wherein thetransmit and receive frequencies of controller 1 or controller 2 arepreferably sufficiently different such that insignificant interferenceis encountered, as will be apparent to those of skill in the art.Alternatively, the transmit and receive frequencies may be identical,but may employ the use of pseudorandom noise codes for spread spectrumcommunications, or time division multiple access, for example, as willbe apparent to those of skill in the art. The use of PN codes mayadditionally reduce the chance of an external noise source having anadverse effect on system compatibility, such as electrical device noisein a medical or office setting. Alternatively, addressing may be used todifferentiate between signals on the same frequency, as will be apparentto those skilled in the art.

FIG. 5 is a block diagram illustrating an embodiment of the presentinvention wherein an interface, such as a wireless interface, may beutilized between controller 1 and controller 2 of the portable weighingdevices 100 a,b, and wherein a wireless interface may be utilizedbetween at least one of controllers 1 and 2 and the handheld controller202 or the record server interface 204. The wireless interface(s) 502and/or 504 and/or 506 may be any wireless interface known to thoseskilled in the art, such as an RF interface or an infrared interface.The interface(s) may be bi-directional in that the handheld controller202, or the record server interface, may query controller 1 andcontroller 2 to request the most recently acquired weight data.Controllers 1 and 2 214, 218 may then respond to the data request byproviding the weight data samples to the handheld controller 202 orrecord server interface. Alternatively, controller 2 may communicatewirelessly, or via wired connection, with controller 1, and controller 1may communicate the data from controllers 1 and 2 wirelessly to one ofthe handheld controller or the medical record server interface.

The wireless interfaces 502 and/or 504 may include an RF interfacewherein the transmit and receive frequencies of controller 1 andcontroller 2 are sufficiently different, such that insignificantinterference is encountered as will be apparent to those of skill in theart. Alternatively, the transmit and receive frequencies may beidentical between controller 1 214 and/or 2 218 and/or the handheldcontroller 202, but may employ the use of pseudorandom noise codes forspread spectrum communications, or time division multiple access, forexample, as is known to those of skill in the art. The use of PN codesmay reduce the chance of an external noise source having an adverseeffect on system compatibility in the medical or office setting.Alternatively, addressing may be used to differentiate between signals,as will be apparent to those skilled in the art.

Wireless interface 506 may be used to transmit the sampled weight datafrom a handheld controller 202 to the medical record server interface204.

Alternatively, as set forth hereinabove, the sampled weight data may betransmitted directly to the record server interface 204 from thecontrollers 1 and/or 2.

FIG. 6 is a block diagram illustrating an embodiment of the presentinvention, wherein a wireless interface is utilized between controller 1of the portable weighing devices 100 a,b and the handheld controller 202or record server interface. The wireless interfaces 602 and/or 506 maybe any interface known to those skilled in the art, such as an RFinterface or an infrared interface. The interface may be bi-directionalin that the handheld controller 202, or record server interface 204, mayquery controller 1 to request the most recently acquired weight data.Controller 1 214 may then query controller 2 218 for the most recentlyacquired weight sample data.

FIG. 7 illustrates an embodiment of the present invention wherein fourportable weighing devices 212, 216, 712, 716 are utilizedsimultaneously. This configuration allows the weighing of a patient on awheelchair, a standard chair, or even a bed. In the FIG. 7configuration, each portable weighing device is preferably similar infunction to the portable weighing devices discussed hereinabove. Thefour portable weighing devices may differentially weigh a wheelchair,and the patient therein, without using mathematical algorithms, otherthan subtraction of the weight of the wheelchair, to generate thepatient weight. The four portable weighing devices may includecommunications interfaces, wherein it may be necessary to havedifferences in frequencies to accommodate the electromagneticcompatibility of a wireless embodiment of the system, as set forthhereinabove. In one embodiment, all four portable weighing devices maythus transmit and receive on different frequencies. The handheldcontroller may accommodate the wired, or the wireless, transmission andreception of the four different receive/transmit channels.

In an additional embodiment, all four portable weighing devices 100 a,band 700 a,b may receive on the same frequency, such as the transmitfrequency of the handheld controller. Additionally, the four portableweighing devices 100 a,b and 700 a,b may transmit on the same frequency,such as the receive frequency of the handheld controller. The transmitand receive frequencies of the handheld controller may be appropriatelydivergent to allow for electromagnetic compatibility, as is well knownby those of skill in the art. The handheld controller 202 may issuecommands to the portable weighing devices individually, such as viadigital addressing of the portable weighing devices, and each device mayrespond by providing a weight sample back to the handheld controller202, for example. Such an exemplary embodiment may utilize a singletransmit and receive frequency for all four weighing devices, whereineach device is assigned a unique address, and wherein the handheldcontroller interfaces uniquely, via the addressing, to each of the fourdevices. Contention for frequency use may additionally be eliminated bytime division data traffic control of the handheld controller 202, suchas time division multiplex control by the handheld controller, forexample, or by frequency division, as set forth hereinabove. Thefrequencies of transmission and/or reception between the handheldcontroller 202 and the medical record server interface 204, depicted aslink 506 in FIG. 7, may be different from the frequencies used by theportable weighing devices 100 a,b and 700 a,b, as will be apparent tothose skilled in the art.

FIG. 8 is a flowchart illustrating a process in an embodiment of thepresent invention utilizing two portable weighing devices, such asillustrated in, for example, FIGS. 2, 4, 5, and 6. The process may bestarted at step 802, such as by the user, such as an operator of thehandheld controller, starting a new measurement 804.

After initialization 804, the user is queried as to whether the patientwill be weighed with a wheelchair. If the user indicates that thepatient will be weighed in a wheelchair, step 810 queries whether thewheelchair weight was previously entered, or is known. If the wheelchairneeds to be weighed, step 812 prompts the user to place the front casterwheels of the empty wheelchair on the scales. A weight measurement istaken of the empty wheelchair by the portable weighing devices andreported back to the handheld controller. Next, the weight of the backor main wheels of the wheelchair may be measured 814 by prompting theuser to place the wheelchair main wheels on the portable weighing pads.

Note that if the wheelchair measurement is already entered, or is knownby the user, the program may skip from step 810 to step 816 and startthe patient weighing process directly. At step 816, the handheldcontroller may prompt the user to place the front wheels of the occupiedwheelchair on the portable weighing device for a measurement of thepatient weight. Once the measurement is taken, the handheld controllerdisplays to the user the request to place the main wheels of theoccupied wheelchair on the portable weighing devices in order tocontinue patient weighing 818. Thereby, the final total weight isgenerated.

The known weight of the wheelchair is subtracted from the total weightmeasured at step 820, and the weight of the patient is thereby providedto the medical server at step 822. The patient weight may be displayedto the user, and the process may return to the idle state at step 802.

If an ambulatory patient is to be weighed, the process may allow theuser to directly weigh the patient via link 808 in FIG. 8. Withreference to FIG. 9, the handheld controller may instruct the user toplace a cover over the wheelchair wheel depression, in an embodimentwherein the load cell is not shaped to accept a human foot, which allowsthe portable weighing device to directly measure the weight applied tothe cover. Thus, an ambulatory patient may step directly onto theportable measuring devices and be weighed without the use of awheelchair.

If need be, the covers are in place at step 902, and the patient standson the transducer of the portable weighing devices and is weigheddirectly. Step 906 displays the weight to the user. Step 908 allowsuploading of the measurement directly to a patient record serverinterface. Once the data is transferred, the handheld controller may beplaced in the idle state at step 802.

It will be apparent to those skilled in the art that variousmodifications and variations may be made in the apparatus and process ofthe present invention without departing from the spirit or scope of theinvention. For example, in each of the embodiments set forthhereinabove, the weight of a patient may be digitally displayed,preferably in real time, on the handheld controller, on a nearbycomputer, or on the load cells, and may be displayed in any applicableweight measure type, such as lbs. or kgs. Further, in each of theembodiments set forth hereinabove, the weighing system may have a powersaving mode, such as wherein the system powers down after a specifiedtime of non-use, such as 10 minutes, for example. Thus, it is intendedthat the present invention cover the modification and variations of thisinvention provided they come within the scope of the appended claims andtheir equivalents.

1. A system for measuring weight of at least one patient in a fourwheeled wheelchair, comprising: at least two portable weight measurers,wherein each of said weight measurers is corresponded to a weightimposed on a corresponded one of at least two wheels of the four wheels,and wherein a first of the corresponded weights from a first of the atleast two weight measurers is accumulated at a second of the at leasttwo weight measurers with a second of the corresponded weights into anaccumulated weight measure; a receiver, wherein said receiver receivesthe accumulated weight measure from at least the second of the at leasttwo weight measurers; and a wireless communicative connection thatconnects each of the at least two portable weight measurers to allow forthe accumulated weight measure.
 2. The system of claim 1, wherein saidwireless communicative connection is at least one selected from thegroup consisting of a radio frequency interface and an infraredinterface.
 3. The system of claim 2, wherein said radio frequencyinterface comprises a single transmit and receive frequency, and whereinisolation of data flow between said portable weight measurers comprisesat least one selected from the group consisting of pseudorandom noisecodes, data addressing, and time division multiplexing.
 4. The system ofclaim 1, wherein said receiver comprises a medical record serverinterface, wherein said medical record server interface accepts theaccumulated weight measure for storage in at least one patient recorddatabase.
 5. The system of claim 4, wherein said receiver furthercomprises a controller, wherein said controller accepts the accumulatedweight measure for forwarding to at least one patient record database.6. The system of claim 5, further comprising a receiver interfacebetween said controller and said medical record server interface.
 7. Thesystem of claim 1, further comprising a wireless interface between atleast the second of the at least two portable weight measurers and thereceiver.
 8. The system of claim 1, wherein each of said at least twoportable weight measurers comprises at least one transducer.
 9. Thesystem of claim 8, wherein each of said at least two portable weightmeasurers further comprises at least one transducer controller.
 10. Asystem for measuring weight of at least one patient in a wheelchair,wherein the wheelchair includes at least two front wheels and two rearwheels, comprising: two portable weight measurers, wherein each of saidweight measurers is corresponded to a weight imposed on a correspondedone of two wheels of the at least two front wheels and two rear wheels,and wherein a first of the corresponded weights from a first of the twoweight measurers is accumulated at the second of the weight measurerswith a second of the corresponded weights to generate an accumulatedweight measure; a wireless communicative connection that connects eachof the two portable weight measurers to allow for the accumulated weightmeasure; and a calculator that calculates the weight of the at least onepatient in accordance with a summation of a first of the accumulatedweight measure and a second of the accumulated weight measure.
 11. Amethod of measuring and recording the weight of a patient on awheelchair, comprising: sampling at least a first partial weight of thepatient sitting in the wheelchair by placing a first wheel of thewheelchair on a first portable weight measurer; sampling at least asecond partial weight of the patient sitting in the wheelchair byplacing a second wheel of the wheelchair on a second portable weightmeasurer; wirelessly communicating the first partial weight to thesecond portable weight measurer; accumulating the first partial weightand the second partial weight; calculating the weight of the patient inaccordance with said accumulating and a subtracting of a wheelchairweight from said accumulating; and transmitting the weight of thepatient to a patient record for storage.